After running 3 or 4 days worth of instances (using Recount), I see that I'm getting between 4.8% and 5.3% critical rate with my Thuder Clap ability. The main reason I took Incite was to increase my utility when AOE tanking.

When any skill or talent in WoW reads, "...increases the {statistical} chance of {anything} by x%," what that means is that it is increasing the already existing chance by x% of that chance, not directly adding x% to that chance. The property of this phrasing is multiplicative, not additive.

To explain myself, let's say your Thunderclap was at a 5% crit chance before you spec'd into Incite. The math on Thunderclap with Incite would then be:

current crit chance + (current crit chance * .15)

or

5 + (5 * .15)

or

5.75

In this case, your crit chance only went up by .75% (not even a full percentage), and you used up three talent points to get it. Before Incite is worth anything to you, I should think you would need a significant amount of crit chance percentage.

When any skill or talent in WoW reads, "...increases the {statistical} chance of {anything} by x%," what that means is that it is increasing the already existing chance by x% of that chance, not directly adding x% to that chance. The property of this phrasing is multiplicative, not additive.

To explain myself, let's say your Thunderclap was at a 5% crit chance before you spec'd into Incite. The math on Thunderclap with Incite would then be:In this case, your crit chance only went up by .75% (not even a full percentage), and you used up three talent points to get it. Before Incite is worth anything to you, I should think you would need a significant amount of crit chance percentage.

This is incorrect for this particular talent.

Incite does increase your chance to crit by 15% for the listed abilities. A little checking around at Elitist Jerks or TankSpot will confirm this.

Incite does increase your chance to crit by 15% for the listed abilities. A little checking around at Elitist Jerks or TankSpot will confirm this.

Then he is in fact experiencing some kind of glitch. The results he is experiencing support my mathematics, but EJ and TS support yours. Perhaps the OP's crit rating was so low to begin with that all he really has is about 16-18% total? I went and looked up TS's discussion on the issue, and the only other thing I can think from reading it that would be an issue with not seeing as many results from Incite as you'd like is not having enough uptime on your Heroic Strike. Perhaps this is worth further investigation by someone who knows Warriors significantly better.